Improving the Performance of Zn-Air Batteries with N-Doped Electroexfoliated Graphene

The constantly growing demand for active, durable, and low-cost electrocatalysts usable in energy storage devices, such as supercapacitors or electrodes in metal-air batteries, has triggered the rapid development of heteroatom-doped carbon materials, which would, among other things, exhibit high catalytic activity in the oxygen reduction reaction (ORR). In this article, a method of synthesizing nitrogen-doped graphene is proposed. Few-layered graphene sheets (FL-graphene) were prepared by electrochemical exfoliation of commercial graphite in a Na2SO4 electrolyte with added calcium carbonate as a separator of newly-exfoliated FL-graphene sheets. Exfoliated FL-graphene was impregnated with a suspension of green algae used as a nitrogen carrier. Impregnated FL-graphene was carbonized at a high temperature under the flow of nitrogen. The N-doped FL-graphene was characterized through instrumental methods: high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Electrochemical performance was determined using cyclic voltamperometry and linear sweep voltamperometry to check catalytic activity in ORR. The N-doped electroexfoliated FL-graphene obeyed the four-electron transfer pathways, leading us to further test these materials as electrode components in rechargeable zinc-air batteries. The obtained results for Zn-air batteries are very important for future development of industry, because the proposed graphene electrode materials do not contain any heavy and noble metals in their composition.

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Bifunctional electrochemical properties of La0.8Sr0.2Co0.8M0.2O3-δ (M= Ni, Fe, Mn, Cu): efficient elemental doping based on structural and pH-dependent study

Materials Advances ◽

10.1039/d1ma00632k ◽

2021 ◽

Author(s):

Junfang Cheng ◽

Pandian Ganesan ◽

Ziling Wang ◽

Ming Zhang ◽

Guozhu Zhang ◽

...

Keyword(s):

Catalytic Activity ◽

Oxygen Reduction Reaction ◽

Oxygen Evolution Reaction ◽

Low Cost ◽

Perovskite Oxides ◽

Reduction Reaction ◽

High Catalytic Activity ◽

Suitable Candidate ◽

Ph Dependent ◽

Elemental Doping

Perovskite oxides with a low cost and high catalytic activity are considered as suitable candidate for oxygen evolution reaction (OER)/oxygen reduction reaction (ORR), whereas most of them favor only either...

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Ordered Intermetallic Nanoparticles with High Catalytic Activity Prepared by an Electrochemically Induced Phase Transformation

10.26434/chemrxiv.8289812 ◽

2019 ◽

Author(s):

Du Sun ◽

yunfei wang ◽

Kenneth Livi ◽

chuhong wang ◽

ruichun luo ◽

...

Keyword(s):

Catalytic Activity ◽

Diffusion Mechanism ◽

Reduction Reaction ◽

Atomic Scale ◽

High Catalytic Activity ◽

Ambient Conditions ◽

Magnetic Devices ◽

Disordered Alloys ◽

Ordered Intermetallic ◽

Intermetallic Nanoparticles

<div> The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered intermetallic PdBi2 to ordered intermetallic Pd3Bi nanoparticles under ambient conditions by an electrochemically induced phase transition. The low melting point of PdBi2 corresponds to low vacancy formation energies which enables the facile removal of the Bi from the surface, while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd3Bi exhibits 11x and 3.5x higher mass activty and high methanol tolerance for the oxygen reduction reaction compared to Pt/C and Pd/C, respectively,which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble metal rich ordered intermetallic phases with high catalytic activity, and sets forth guidelines for the design of ordered intermetallic compounds under ambient conditions. </div>

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A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

Materials ◽

10.3390/ma13030594 ◽

2020 ◽

Vol 13 (3) ◽

pp. 594 ◽

Cited By ~ 3

Author(s):

Mara Serrapede ◽

Marco Fontana ◽

Arnaud Gigot ◽

Marco Armandi ◽

Glenda Biasotto ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Chemical Reduction ◽

Low Cost ◽

Xps Analysis ◽

3D Scaffold ◽

Energy Storage Devices ◽

Reduced Graphene

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

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High catalytic activity for formaldehyde oxidation of an interconnected network structure composed of δ-MnO2 nanosheets and γ-MnOOH nanowires

Advances in Manufacturing ◽

10.1007/s40436-020-00321-2 ◽

2020 ◽

Vol 8 (4) ◽

pp. 429-439

Author(s):

Ying Tao ◽

Rong Li ◽

Ai-Bin Huang ◽

Yi-Ning Ma ◽

Shi-Dong Ji ◽

...

Keyword(s):

Catalytic Activity ◽

Network Structure ◽

Manganese Oxides ◽

Active Oxygen Species ◽

Low Cost ◽

High Dispersion ◽

Hydroxyl Groups ◽

High Catalytic Activity ◽

Interconnected Network ◽

Surface Hydroxyl

AbstractAmong the transition metal oxide catalysts, manganese oxides have great potential for formaldehyde (HCHO) oxidation at ambient temperature because of their high activity, nontoxicity, low cost, and polybasic morphologies. In this work, a MnO2-based catalyst (M-MnO2) with an interconnected network structure was successfully synthesized by a one-step hydrothermal method. The M-MnO2 catalyst was composed of the main catalytic agent, δ-MnO2 nanosheets, dispersed in a nonactive framework material of γ-MnOOH nanowires. The catalytic activity of M-MnO2 for HCHO oxidation at room temperature was much higher than that of the pure δ-MnO2 nanosheets. This is attributed to the special interconnected network structure. The special interconnected network structure has high dispersion and specific surface area, which can provide more surface active oxygen species and higher surface hydroxyl groups to realize rapid decomposition of HCHO.

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Enhanced Activity towards Oxygen Electrocatalysis for Rechargeable Zn-Air Batteries by Alloying Fe and Co in N-doped Carbon

Dalton Transactions ◽

10.1039/d1dt02787e ◽

2021 ◽

Author(s):

Fengjiao Yu ◽

Qi Ying ◽

Shaofeng Ni ◽

Chenxue Li ◽

Daxiang Xue ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Noble Metals ◽

Large Scale ◽

Low Cost ◽

Reduction Reaction ◽

Enhanced Activity ◽

Feco Nanoparticles

Large-scale application of rechargeable Zn-air batteries requires low-cost electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as alternatives to noble metals. Herein, FeCo nanoparticles embedded in N-doped...

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Molten salts-assisted synthesis of special open-cell Fe, N co-doped porous carbon as an efficient electrocatalyst for zinc-air batteries

New Journal of Chemistry ◽

10.1039/d1nj04582b ◽

2021 ◽

Author(s):

Xiaoying Gao ◽

Xuan Xie ◽

Kanjun Sun ◽

Xiaofei Lei ◽

Tianyu Hou ◽

...

Keyword(s):

Catalytic Activity ◽

Porous Carbon ◽

Molten Salts ◽

Low Cost ◽

High Catalytic Activity ◽

Open Cell ◽

Co Doped ◽

Excellent Stability ◽

Zinc Air Batteries

Fe, N co-doped carbon electrocatalyst is one of the most attractive alternatives to Pt/C catalysts due to its high catalytic activity, excellent stability and low cost. However, obtaining stable and...

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A Review of Supercapacitors Based on Graphene and Redox-Active Organic Materials

Materials ◽

10.3390/ma12050703 ◽

2019 ◽

Vol 12 (5) ◽

pp. 703 ◽

Cited By ~ 16

Author(s):

Qi Li ◽

Michael Horn ◽

Yinong Wang ◽

Jennifer MacLeod ◽

Nunzio Motta ◽

...

Keyword(s):

Electrode Materials ◽

Low Cost ◽

Lithium Ion ◽

Dimensional Structure ◽

Future Research ◽

Synthesis Methods ◽

Energy Storage Devices ◽

Storage Devices ◽

Redox Active ◽

Recent Developments

Supercapacitors are a highly promising class of energy storage devices due to their high power density and long life cycle. Conducting polymers (CPs) and organic molecules are potential candidates for improving supercapacitor electrodes due to their low cost, large specific pseudocapacitance and facile synthesis methods. Graphene, with its unique two-dimensional structure, shows high electrical conductivity, large specific surface area and outstanding mechanical properties, which makes it an excellent material for lithium ion batteries, fuel cells and supercapacitors. The combination of CPs and graphene as electrode material is expected to boost the properties of supercapacitors. In this review, we summarize recent reports on three different CP/graphene composites as electrode materials for supercapacitors, discussing synthesis and electrochemical performance. Novel flexible and wearable devices based on CP/graphene composites are introduced and discussed, with an eye to recent developments and challenges for future research directions.

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Single-atom transition metals supported on black phosphorene for electrochemical nitrogen reduction

Nanoscale ◽

10.1039/c9nr09117c ◽

2020 ◽

Vol 12 (8) ◽

pp. 4903-4908 ◽

Cited By ~ 15

Author(s):

Kang Liu ◽

Junwei Fu ◽

Li Zhu ◽

Xiaodong Zhang ◽

Hongmei Li ◽

...

Keyword(s):

Catalytic Activity ◽

Transition Metals ◽

Reduction Reaction ◽

Single Atom ◽

High Catalytic Activity ◽

Nitrogen Reduction ◽

Mild Conditions ◽

Black Phosphorene

Electrochemical nitrogen reduction reaction (NRR) is a promising route to produce ammonia under mild conditions. Single-atom W supported on BP was screened as a promising electrocatalyst with high catalytic activity, stability, and selectively for NRR.

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Improvement of Catalytic Activity of Platinum Nanoparticles Decorated Carbon Graphene Composite on Oxygen Electroreduction for Fuel Cells

Processes ◽

10.3390/pr7090586 ◽

2019 ◽

Vol 7 (9) ◽

pp. 586 ◽

Cited By ~ 7

Author(s):

Halima Begum ◽

Young-Bae Kim

Keyword(s):

Catalytic Activity ◽

Fuel Cells ◽

Surface Area ◽

High Performance ◽

Pt Nanoparticles ◽

Reduction Reaction ◽

Graphene Sheets ◽

Crossover Effect ◽

Onset Potential ◽

Monolayer Dispersion

High-performance platinum (Pt)-based catalyst development is crucially important for reducing high overpotential of sluggish oxygen reduction reaction (ORR) at Pt-based electrocatalysts, although the high cost and scarcity in nature of Pt are profoundly hampering the practical use of it in fuel cells. Thus, the enhancing activity of Pt-based electrocatalysts with minimal Pt-loading through alloy, core−shell or composite making has been implemented. This article deals with enhancing electrocatalytic activity on ORR of commercially available platinum/carbon (Pt/C) with graphene sheets through a simple composite making. The Pt/C with graphene sheets composite materials (denoted as Pt/Cx:G10−x) have been characterized by several instrumental measurements. It shows that the Pt nanoparticles (NPs) from the Pt/C have been transferred towards the π-conjugated systems of the graphene sheets with better monolayer dispersion. The optimized Pt/C8:G2 composite has higher specific surface area and better degree of graphitization with better dispersion of NPs. As a result, it shows not only stable electrochemical surface area but also enhanced ORR catalytic activity in respect to the onset potential, mass activity and electron transfer kinetics. As shown by the ORR, the Pt/C8:G2 composite is also better resistive to the alcohol crossover effect and more durable than the Pt/C.

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One-pot synthesis of Co/N-doped mesoporous graphene with embedded Co/CoOx nanoparticles for efficient oxygen reduction reaction

Nanoscale ◽

10.1039/c7nr03897f ◽

2017 ◽

Vol 9 (29) ◽

pp. 10233-10239 ◽

Cited By ~ 40

Author(s):

Yanli Niu ◽

Xiaoqin Huang ◽

Xiaoshuai Wu ◽

Lei Zhao ◽

Weihua Hu ◽

...

Keyword(s):

Catalytic Activity ◽

Fuel Cells ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Reduction Reaction ◽

High Catalytic Activity ◽

One Pot ◽

One Pot Synthesis

Exploration of sustainable electrocatalysts toward oxygen reduction reaction (ORR) with high catalytic activity remains a key challenge in the development of metal–air batteries and fuel cells.

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